Laser Doppler Vibrometry system using the synthetic-heterodyne interferometric demodulation scheme implemented on a CMOS DSP camera

A laser Doppler vibrometer (LDV) is described which uses a CMOS digital camera, incorporating a digital signal processor, to carry out real-time signal processing of the interferometer output to allow multipoint LDV to be implemented. The synthetic-heterodyne technique is used to overcome the interferometric fading effect due to slow environmental changes. Vibration frequencies up to 100 Hz were detected successfully.